Centrifugal device



CENTRIFUGAL DEVICE 3 Sheets-Sheet 1 Filed Hay 7, 1954 FIC-3.1

Feb. 12, 1957 W; G. J. Hmm/,ANN 2,781,131

CENTRIFUGAL DEVICE s sheets-sheet 2 Filed May 7, 1954 Feb 12, 1957 w. G.J. HECKMANN 2,781,131

CENTRIFUGAL DEVICE Filed May 7, 1954 3 Sheets-Sheet 3 FIC-5.3

INVENTDP 44%.?. @Anl .7074 #fm1/nw United States Patent O CENTRIFUGALDEVICE Wolfgang Gertrud Joseph Heckmann, Koln-Deutz, Germany, assignorto Klockner-Humholdt-Deutz A. G., Koln, Germany, a corporation ofGermany Application May 7, 1954, Serial No. 428,266

32 Claims. (Cl. 210-72) The present invention relates to a centrifugaldevice, and more particularly to a centrifugal device or centrifuge fordehydrating a fine-granular material, and to a method for dehydratingthe same.

Centrifugal devices of this kind are known in the art, in which a sievedrum being open at the upper end thereof is resiliently arranged on adriving member. The material is removed from the drum by axialvibrations which are imparted to the sieve drum.

It is an object of the present invention Vto provide an improved andcompact design of such centrifugal devices which has particularly theadvantage of being closed from all sides.

1t Vis another object of the present invention to make use of resonancephenomena of the vibrations ofthe sieve drum.

It is a further object of the present invention -to render the sievedrum capable o an automatic adjustment thereof.

lt is still another object of the present invention to improve thedehydration of the material fed to-the centrifugal device according tomy invention.

It is a still further object of my invention to Aimprove ythe yield ofsolid particles obtained by the sieve drum.

Other objects and structural details ofthe present invention will becomeapparent from the following detailed description thereof when read inconnection with the acv companying drawings forming part of thisspecification, wherein:

Fig. l is a sectional elevation of a rst embodiment of a centrifugaldevice according to the present invention;

Fig. 2 is a horizontal sectional View of the centrifugal device shown inFig. 1, taken on line ll-llof Fig. l;

Fig. 3 is a sectional-elevation of a second embodiment of a centrifugaldevice according to the present invention; and

Fig. 4 is, on lan enlarged scale, a section of a detail of the deviceshown in Fig. 3.

Referring now to the drawing and lirst to Figs. l and 2, it will be seenthat a sieve drinn V1 is shaped as a frustum of a hollow invertedcircular cone having a substantially vertical axis and which is open atthe upper end thereof. At the lower end of the sieve drum 1 asubstantially horizontal ring-shaped base member or plate 2 is arrangedwhich is preferably offset so as to form substantially horizontal outerand inner portions 2', 2" connected with yeach other by a substantiallyvertical portion 2"', the outer portion 2 being arranged at a higherlevelthan the inner portion 2". A substantially conical cap 3 isattached to the upper or outer portion 2" of the base member 2by meansof the lower marginal portion 3 of thecap 3 so that the cap 3 protectsthe bearings and springs more fully to be described hereinafter, againstVwater'and dirt.

A stationary member 4 designed as -a hollow vertical shaft rigidlyconnected to the frame 5 of the machine projects with'its upper end intothe conical cap 3. A hollow vertical body or actuating means 8 formingparte-of Lthe ICC actuator for producing rotations of the sieve drum 1surrounds part of the stationary shaft 4 against which it abuts by firstand second bearings 6 and 7, respectively, the first bearing 6 beingenclosed by the cap 3.

The actuating means or body 8 has an outer collar 9 (termed hereinafterthe lower outer portion) forming one piece therewith. Along the outerpart of the collar 9 are arranged vibrating bodies or members 10 (termedhereinafter the second vibrating bodies or members) which abut againstthe outer portion 2 of the base plate 2. Furthermore vibrating bodies ormembers 11 (termed hereinafter the first kvibrating bodies or members)are arranged onthe inner olset portion 2 of the base plate 2 and abutagainst a ring 12 (termed hereinafter the upper outer portiou) which issecured to the body 8 byrueans of a screw-threaded portion 8. Thevibrating bodies 10 and 11 are termed hereinafter collectively thesecond ref sirlient means, and are designed preferably as helicalsprings ,as shown in the drawing; however, they `can he replaced, -ifdesired, by rubber blocks (not shown), preferably of ,cylindricalcross-section. Thevibrating bodies or members 10, 11 are inserted insuitable recesses (not shown) of the base plate 2, the Vcollar .9, andthe ring'lZ inorder to impart to the bodies or members 10, `11 Awelldefined lpositions relative to the parts 2, 9 and f-I-,he bodies 10, 11thus serve for transferring the torque `from the body 8 to the baseplate 2 and to the sieve drum v1 rigidly connected thereto.

The lower portion 8 of the body or actuating means 8 which is arrangedbelow the collar 9 is designed as a pulley provided with grooves 13 forV-belts indica-ted by the dashdotted lines 44 which engage a secondpulley 35 attached to the upper portion of a shaft 36 of a iirst drivingmotor 14 secured to the frame 5 of the machine. The driving motor 14,the body S and 4the belt-drive connecting same representan actuator forrotating the sieve drum 1.

The upper or first bearing 6 is protected by a cap 15 against dust and/or moisture. The cap 15 is held in position by an annular nut 16 screwedto the uppermost portion o f the stationary member 4 and projects withits rim portion into a recess 12 of the ring 12. The second bearing 7 isprotected against dust and/ or moisture by interengaging rings 17, 17'forming part, respectively, of the lower portion S of the rotating body3 and the lower enlarged portion 4 of the stationary member orV shaft 4.Y

A substantially horizontal crank shaft 18 is supported by bearings 37arranged in the enlarged portion 4 of the stationary member 4. The crankshaft 1S is coupled by a coupling 38 with a second driving motor 19secured tothe upper plate 5' of the frame 5 of the machine.

The upperV plate 5 of the frame 5 and the driving motors .14 and 19supported by the sameare enclosed in an inner. casing 29 protecting themotors k14 and 19 largely against damage.

The stationary member or shaft 4 is hollow and serves as a housing -fora connecting rod Ztl the lower end 20 of which engages the bend 13 ofthe crank shaft 1 8. The upper end portion 2Q of the connecting rod 20is pro vided with a loose coupling 21 including a cross member 21connected to the upper end portion 26 of the connect? ing rod Ztl andtwo compression springs 21 abutting against collars such as 20' of theupperend portionp20i and against the cross member 21 from dilerentsides.

The loose coupling 1 is connected throughrresilient bearings 22 with ablock 3 attached to the cap 3. VInY consequence thereof the sieve drum 1is imparted axial vibrations by the connecting rod 20, the latter beingcoupled therewith by the loose coupling 21'connected to the cap 3 rigidwith the base plate 2 rigidly connected to .tnesieve drum 1.

Thus the crank shaft 18, the connecting rod 20-and the loose'coupling-21 form a vibrator or `a ydevice -for imparting to the sieve drum 1vibrating movements in the axial direction thereof. revolutions perminute of the crank shaft 1S is chosen in such manner'that the naturalfrequency of the sieve drum V1, i. e..the frequency of the verticalvibrating movements of the sieve drum 1 supported by the vibratingbodies 10, 11 is in resonance with the frequency of the vibrator formedby the crank shaft 18, the connecting rod 20 and the loose coupling 21.

An annular container 23 is arranged outside and below the sieve drum 1and provided with an outlet 34. The upper rim portion 24 of the sievedrum 1 forms a gap together with a ring-shaped member 24 which isengaged by the upper rim portion 40 of the container 23. The innercasing 29 and `the container 23 'are surrounded by an outercasing 26forming an annular space 25 with the vcontainer 23 and the inner casing29 which opens at the bottom into a collecting bin 31 formed by afoundation 'or supporting means 28 supporting the frame 5 of the machineVby means of Vfirst resilient means designed as soft Vsprings 27, i. e.as springs lhaving ay low spring constant. The outer casing 26 issecured to the outer rim portion 5" of the frame 5 connected bystitfening ribs 32 .with the main portion 5 of the frame 5. Thus it isseen that the casings 26 and 29 are rigidly connected to the frame 5.

Between the vibrating springs arranged'on the collar 9 `are placedrubber springs such as 30 having a very progressive characteristic, i.e. the spring constant thereof increases with the compression of thesesprings. The rubber springs 30 are preferably spherical at the uppersides thereof and become operative in the last third of the vibratingpath of the springs 10.

The operation of this device is as follows:

T'he motors 14 and 19 are started so :that the sieve drum 1 is rotatedby the motor 14 over the second pulley 35, the V-belts 44, the firstpulley 13 Iand the rotating body 8 transferring its rotation by .thesprings 10, 11 to the base plate 2 rigidly connected to the sievedrum 1. At the same time the motor 19 drives over the crank shaft 18 theconnecting rod 20 carrying out upward and downward movements which aretransferred as vibrations by the loosercoupling 21 to the conical cap 3rigidly connected to the base plate 2 rigid with the sieve drum 1. f Thematerial to be dehydrated is filled into the interior of thesieve dmm 1between the latter and the conical cap v3. The liquid contained in thematerial to be dehydrated is carried through the perforated wall of thesieve drum 1 and is caught in the annular container 23 from which itescapes through the outlet pipe 34. The dehydrated material moves underthe action of the centrifrugal force upward to the rim portion 24 andinto the annular space 25 from where it is discharged into thecollecting bin'31.

The dehydrating centrifuge includes thus a two-mass system, the sievedrum 1 with the parts rigidly connected therewith forming the firstmass, and the frame 5 together with the driving devices and :the casings26 and 29 forming the second or counter-mass.

Y During operation Vthe sieve drum 1 and the parts rigidly connectedtherewith vibrate in a direction opposite to that in which thecounter-mass vibrates so that a very favorable balancing of the massesis obtained. Preferably the vibrations of the sieve drum 1 have only anamplitude of v temporary differences in the load thereof such as thosecaused by a non-uniform or intermittent charging of the4 Preferably thenumber of thereof.

sieve drum 1. Thus it is seen that the rubber springs 30 limitundesirable vibrating movements. This effect is particularly favorableif the vibrating springs 10 and 11 dimensioned in axial direction forresonant operation, are arranged at such distances from the axis thatthe transversal and/or torsional vibrations in the direction indicatedby the arrow 33 are hypercritical. In such a case the sieve drum 1 hasthe tendency to adjust itself automatically to the free axis thereof,the free axis corresponding to the geometrical axis of the sieve drum1.V Referring now to Figs. 3 and 4, it will be seen that the centrifugaldevicev comprises a drum 101 open at the upper end thereof and having afrusto-conical sieve jacket 135 the generatrix of which is'inclined byan angle of 8-18, preferably 10., to the axis A-A of the drum. The meandiameter of the drum 101 measured at half the height thereof amounts toapproximately 900 millimeters. The sieve openings of the jacket 135 arepreferably designed as horizontal slotsr136 (Fig. 4) each having aWedge-shaped cross-section having `anV opening width amounting, forinstance, to 0.5 millimeter at the inner side thereof, and to 0.8millimeter at the outer side At the lower side the drum 101 is closedVby a base plate 102 which is preferably offset as the base plate 2shown in Fig. l. A cap 103 shaped as a frustum of cone having ahorizontal upper end plate 103 is attached to the base plate 102 in thesame manner as the cap 3 shown in Fig. l is attached to the base plate2.

The cap 103 is connected by means of ribs 137 and 138 to a cone-shapedshell 139 enclosing a free space 140 with the cap 103. The lower rim 161of the cone-shaped shell 139 is arranged Iat a distance from and abovetheV base plate 102 so as to form a gap 141.

At the upper side the cone-shaped shell 139 is continued by a hollowcylindrical piece 142 through which passes a stationary feed pipe 143for the material to be fed to the centrifugal device.

' A Ystationary member 104 designed as a hollow vertical shaft rigidlyconnected to the frame 105 of the machine projects with its upper endinto the frusto-conical cap 103 and is surrounded by the hollow verticalbody or actuating means 108. The hollow vertical body 108 is rotatablysupported by iirst and second bearings 106 and 107 and provided with anouter collar or lower outer portion 109 along the outer part of whichare arranged second vibrating bodies or members such as helical springs110 abutting against the base plate 102. Furthermore, first vibratingbodies or members such as helical springs 111 are arranged on the inneroffset portion of the base plate 102 and labut against an upper outerportion such as a ring 112 screwed by an internal thread thereof to ascrew-threaded portion 108' lof the body 108. The first and secondvibrating bodies may be designed, if desired, as cylindrical rubberblocks (not shown) inserted in suitable recesses (not shown) of th'ebase plate-102, the collar 109 and the ring 112.

The upper or first bearing 106 is protected by a cap 115 against dustand/or moisture. The cap is held in position by an annular nut 116screwed to the uppermost portion of the stationary member 104 andprojects with its portion into a recess 112 of the ring 112. The

second bearing 107 is protected against dust and/ or mois- Y ture byinterengaging rings 117, 117' forming part, respectively, of the lowerportion 108" of the rotating body 108 and the lower enlarged portion104' of the stationary member or shaft 104.Y

vBelow the collar 109 the lower portion 108 of the body v10S is providedwith grooves 113 for the reception of V-belts 147 engaging a (second)pulley 146 driven by a (first) driving motor 114 supported by the frame105 of the machine. The driving motor 114, the body 108 and thebelt-drive connecting'same represent `an actuator for rotating the sievedrum. As pointed out hereinabovein the description :of the operationofthe first embodiment Vofthe present invention shown in Figs. l

anti-2 having analogous parts, the torquetransfered frodi the motor 114by means `of the parts 146 and 141 td the body S is transferred by thesprings 11,70 and 111 tothe 101 so that the latter rotates with the body108 and makes, e. g., 400 revolutions per minute. As this number ofrevolutions per minute prevails at half the height of the drum 101, i.e., where the diameter of the same v'amounts to 900 millimeters and atthe perimeter to the drum 101 a centrifugal acceleration m2 where 1' isthe mean radius of the drum 101 and w the angular velocity thereof, thecentrifugal acceleration thus depending on the angular velocity of thedrum 101 and being at 400 revolutions per minute equal to see.

so thatfor the centrifugal acceleration results approXimately 79000cm./se c.2 which Vis about the SO-fold of the acceleration of gravity.VvGenerally the number of revolutions per minute of the drum 101 shouldbeso chosen thatrat half the height thereof a centrifugal accelerationprevails which is the 60 to 90 fold' of the acceleration of gravity.

In the' enlarged portion 104 of the stationary member 104' isV arrangedfor' rotation a substantially longitudinal crank shaft 11S having'asmall bend 118' of'e. g. 2.5 millimeters. The crank shaft 11S is coupledwithv alsecond driving motor 119 supported by the frame 105 of themachine. g A connecting rod 120 the lower end 120V of which engages thebend 118' of the crank shaftf118, passes through the hollow member 104and is provided at the upper en d 120 thereof with an elastic coupling121 operatively connected with a plate 150 held for rotation by meansof'ball bearings 122, but axially indisplaceably in an intermediate wall151 of the cap 103. Inoperation the drum 101 is imparted axialoscillations by the crank drive 1S and the cap 103, said oscillationshaving a frequency of -30 cycles per second and an amplitude of l-3millimeters, the optimal result being achieved with a frequency ofcycles per second and an amplitude of 3 millimeters.

The drum 101 is surrounded by an annular container 123 provided with anoutlet 152. Below the container 123 is arranged an inner casing 129which rests on the frame' of the machine and protects the motors 114 and119 against dirt and/or moisture. The outer cover is formed by acylindrical casing 125 defining an annular space 125 with the container123 and the inner casing 129.' The outer casing 126 is supported by theouter rim portion 105" of the frame 105 which is provided with recesses132 forming the continuations of the annular space 125. rThe recesses132 open into the upper part of a collecting bin 131. The casing issupported by springs 127 supported in turn by the foundation 125.

Thus the device comprises again two masses, one being formed by the drum101, the cap 103, and the conical shell 139,'this being the first orworking mass, whereas the second or counter-mass is formed by the frame105 including the driving means, Vthe inner casing 129, the container123 andthe louter casing 126. The ratio between the working mass and thecounter-mass is very small and amounts preferably to 1:8 to l:l5 as inthe rst embodiment. Therefore the .amplitude of the oscillatlons orvibrations of the counter-mass is relatively small. Preferably the totalspring constant of the springs 110 and 111 is so tuned to the workingmass that the axial oscillationsor vibrations are carried out inresonance.

in operation a coal (anthracite), preferably after first 'removing thedust and consecutive washing, is fed to the centrifugal device by thefeed pipe 143, said coal having a grain size of less than l0 millimeterswith a grainsize fraction of below 0.5 millimeters, and a water contentof approximately 25%. When the fine coal impi'nges on the upper endplate 103 of the cap 103 it is driven by the action Vof the lcentrifugalforce towards the outside vwhere it hits the cone-shaped shell 139. Thenthe 6 coal traverses" the annular space and isv thrown by" centrifugalaction immediately after the exit from the` gap 141 against the sievejacket 13S. Under the inuence of the vibrating movement and thecomponents of the centrifugal force in direction of the generatrices ofthe shell of the drum the ne coal will travel upwards along the.

shell. The `speed of travel is only small owing to the steep slope ofthe jacket 135, the given value of the centrifugal acceleration, and thefrequency and amplitude of the axial vibrations so that the materialremains a relatively long time in the drum 101 so as to be thoroughlydehydrated. Furthermore by the slow advance of the material toward theupper rim portion 124 of the drum 101 it is achieved that at a chargingquantity of e. g. 60 tous per hour a layer of the material is formedhaving a thickness of 10-15, preferably l5 millimeters which acts as afilter on the permeating water and retains a very large quantity of thefine solid components which otherwise would leave through the sieveopenings 136 together with the water. Thus the centrifuged water hasonly a very low coutent of solid constituents which is practicallynegligible. (The water after having passed the sieve drum 101 is caughtin the annular container 123 and discharged through the outlet 152. Thecentrifuged coal leaves the sieve drum 101 over the upper' rim portion124 thereof and falls subsequently through the annular space 125 and therecesses 132 into the collecting bin 131. It should be noted that by thevibrations carried out by the casing and the frame of the machine anyformation of bridges of material are prevented in the space 125 and therecesses 132.

t 'should be understood that numerous changes may be made in the form,construction, and arrangement of the several parts of the illustratedcentrifugal device without departing from the spirit and scope of myinvention or sacrificing any of its attendant advantages, the formherein described being merely for the purpose of illustrating theinvention.

What I claim is:

l. A centrifugal device, comprising in combination: a first system ofmasses including a frame work, an actuator for producing rotatingmovements and a vibrator for producing vibrating movements, saidactuator and said vibrater being mounted on said frame work, a secondsystem of masses including a sieve drum rotatable around itslongitudinal axis, and three resilient means between said first andsecond systems of masses, two of said resilient means opposing eachother and resiliently holding one mass from the other, the third suchmeans resiliently connesting the vibrator to the second mass, all ofsaid resilient means yielding in the direction of the longitudinalaxisof the sieve drum for permitting vibrating movements of said secondsystem of masses in said direction of the longitudinal axis of saidsieve drum, said actuator imparting rotations to said sieve drum, andsaid vibrator imparting vibrating impulses to said sieve drum.

2. In a centrifugal device as claimedin claim l, said sieve drum beingin the shape of a frustum of a hollow cone.

3.111 a centrifugal device as claimed in claim l, said second system ofmasses including a base rigid with said sieve drum, and said two firstmentioned resilient means being engaged with said base and saidactuator.

4. in a centrifugal device as claimed in claim 1, said second system ofmasses including a base rigid with said sieve drum, said base having abore, a portion of said actuator passing through said bore, firstlateral means on said actuator extending at one side of said base,second lateral means on said actuator extending at the other side ofsaid base, said two lirst mentioned resilient means including a firstset of springs and a second set of springs, said first set of springsbeing engaged with said rst lateral means and one side of said base, andsaid second set of springs being engaged with said second lateral meansand the other side of said base.

5. In a centrifugal device as claimed in claim 1, said second system Vofmasses including'a base rigid with said sieve, drum, said base having abore, a portion of said actuator passing through Isaid bore, rst lateralmeans on said actuator extending at one side of said base, secondlateral means on said actuator extending at the other side of said base,said two first mentioned resilient means including a first set ofsprings and a second set of springs, said first set of springs beingengaged with said first lateral means and one side of said base, saidsecond set of springs being engaged with said second lateral means andthe other side of said base, and the radial distance of one of said twosets of springs from the longitudinal axis of said sieve drum beinglarger than the radial distance of the other set of springs from saidlongitudinal axis of the sieve drum.V

Y' 6; In a centrifugal device as claimed in claim 1, said Y secondsystem of masses including a base rigid with said sieve drum, said twofirst mentioned resilient means being engaged with said base and saidactuator, and resilient limiting means attached to one memberV of Vsaidtwo members including the base and the actuator, said resilient limitingmeans being capable of abutting cooperation with the'other of said twomembers so as to limit the relative movement between said two members.

7. A centrifugal device, comprising in combination: a irst system ofmasses including a frame work, an actuator for producing rotatingmovements and a vibrator for producing vibrating movements, saidactuator and said vibrator being mounted on said frame work, a secondsystem of masses including a sieve drum rotatable around itslongitudinal axis, three resilient means between said rst and secondsystems of masses, two of said resilient means opposin-g each other andresiliently holding one mass from the other, the third such meansresiliently connecting the vibrator to the second mass, all of saidresilient means yielding in the direction of the longitudinal axis ofthe sieve drum for permitting vibrating movements of said second systemof masses in said direction of the longitudinal axisV of said sievedrum, and fourth resilient means supporting said system of massesresiliently, said fourth resilient means yielding in the direction ofthe longitudinal axis of the sieve drum for permitting vibratingmovements of -said rst system of masses vin said direction of thelongitudinal axis of said sieve drum, said actuator imparting rotationto said sieve drum, and said vibrator imparting vibrating impulsestosaid sieve drum.

8. In a centrifugal device as claimed in claim 7, said fourth resilientmeans being in the shape of springs having a low spring constant. Y

9. In a centrifugal device as claimed in claim 7, the weight of said rstsystem of masses being at least eight times the weight of said secondsystem of masses.

l0. In a centrifugal device as claimed in claim 7, the weight of saidfirst system of masses being between eight and fifteen times the weightof said second system of masses.

1l. In a centrifugal device as claimed in claim 7, said sieve drum beingin the shape of a frustum of a hollow cone.

l2. In a centrigual device as claimed in claim 7, said second system ofmasses including a base rigid with said sieve drum, and said first andsecond resilient means eing engaged with said base and said actuator.

13. In a centrifugal device as claimed in claim 7, said second system ofmasses including a base rigid Vwith said sieve drum, said base having abore, a portion of said actuator passing through said bore, rst lateralmeans on said actuator extending at one side of said base, secondYlateral means on said actuator extending at the other side of said base,said two first mentioned resilient means including a first set ofsprings and a second set of springs, said first set of springs beingengaged with said first lateral means and one side of said base, andsaid second set of springs being engaged with said second lateral meansand the other side ofsaid base.

Y 14. In a centrifugal device as claimed in claim 7,-said second systemof masses Vincluding av baseV rigid with said sieveV drum, said basehaving a bore, a portion of said actuator passing through saidbore,ftirst lateral means on said actuator extending at one side ofsaid'base; second lateral means on said actuator extending at the otherside of said base, said two first mentioned resilient means including Varst set of springs and a second set of springs, said first set yofsprings being engaged with said first lateral means and one side of saidbase, said second set of springs being engaged with said second lateralmeans and the other side of said base, and the radial distance of one ofsaid two sets of springs from the longitudinal axis of said sieve drumbeing larger than the radial distance of the other set of springs fromsaid longitudinal axis of the sieve drum.

l5. In a centrifugal device as claimed in claim 7, said second system ofmasses including a base rigid with said sieve drum, said two firstmentioned resilient means being engaged with said base and Vsaidactuator, and resilient limiting means Vattached to one member of saidtwo members including the base and the actuator, said resilient limitingmeans being capable of abutting cooperation with the other of said twomembers so as to limit the relative movement between said two members.

16. In a centrifugal device as claimed in claim 7, a resilient couplingarranged between said vibrator and said second system of masses.

l7. A centrifugal device, comprising in combination: a frame work,actuating means rotatably mounted in said Vframe work, a crank mechanismincluding a crank and movements from said actuating means through saidybase to said sieve drum and being yieldable in the direction of thelongitudinal axis of the sieve drum for permitting vibrating movementsof the latter in the direction of its longitudinal axis, a resilientcoupling between said connecting rod of said crank lmechanism and saidsieve drum whereby said crank mechanism may impart vibrating impulses tothe latter, and additional resilient means supporting said frame workresiliently, said additional resilient means yielding in the directionof the longitudinal axis of said sieve drum for permitting vibratingmovements of said frame work and the parts attached theretoin saiddirection of the longitudinal axis of the sieve drum.

18. In a centrifugal device as claimed in claim 17, the connecting rodof said crank mechanism being substantially in register with the centerof said sieve drum, and

saidrotatable actuating means being hollow and surrounding saidconnecting rod. v

19. In a centrifugal device as claimed in claim 1.7, said frame workincluding a hollow center shaft, said actuating means being rotatablymounted on said center shaft, and said connecting rod passing throughthe bore of said center shaft.

20. A centrifugal device, comprising in combination: a frame work,actuating means rotatably mounted in said frame work, a crank mechanismincluding a crank and a connecting rod mounted in said frame work,driving means mounted on said frame work for actuating said actuatingmeans and said crank mechanism, a sieve drum, a base rigid with vsaidsieve drum, the longitudinal axis of said sieve drum coinciding with thelongitudinal assit-s axis of .said aetifatig1neiis, 'said actuatingineens being hollow and surrounding said 'connecting rod, saidconnecting rod being substantially in register with the center of said'sieve "dri, irst and second resilient means engaged with'saidactuatig'means and said base, said rst and second'res'ilit ira'rispp's'iiigeach other and being kcapable "of transmitting tary movementsfrom said actuating means through 'said base to said sieve drum andbeing yieldable i 'the diie'ction of the longitudinal axis of the sievedrum for permitting vibrating movements of the latterwin' theM directionof its longitudinal axis, a rsilientdcoupling between s aid connectingrod and said sieve drum whereby the former may impart vibrating impulsesto the latter, and additional resilient means supporting said frame workresiliently, said additional resilient means yielding in the directionof the longitudinal axis of said sieve drum for permitting vibratingmovements of said frame work and the parts attached thereto in saiddirection of the longitudinal axis of the sieve drum.

21. in a centrifugal device as claimed in 20, a member rigid with thestructure including said sieve drum and base, said resillient couplingincluding a body attached to said connecting rod and rotatably engagedwith said member, a pair of abutting means secured to said connectingrod at opposite sides of said body, `and a pair of `counteractingsprings, one of said springs being engaged with one of said abuttingmeans and `one side of said body, the other spring being engaged withthe other abutting means and the other side of said body.

22. In a centrifugal device as claim-ed in claim 20, said b'ase having abore, said actuating means passing through said bore, a cap rigid withsaid base, said cap covering the end of said actuating means projectingthrough said bore, said resilient coupling including a body attached tosaid connect-ing rod and rotatably engaged with said cap, a pair ofabutting means secured to said connecting rod at opposite sides of saidbody, and a pair of counteracting springs, one of said springs beingengaged with one of said abutting means and one side of said body, theother spring being engaged with the vother abutting means and the otherside of said body.

23. In a centrifugal device as claimed in claim 22, said cap beingsubstantially in the shape of a cone, the apex of which being remotefrom said base.

24. In a centrifugal device as claimed in claim 17, an inner casingattached to said frame work, said inner casing enclosing said drivingmeans.

25. A centrifugal device, comprising in combination: a first system ofmasses including a lframe work, an actuator for producing rotatingmovements and a vibrator for producing vibrating movements, saidactuator and said vibrator being mounted on said frame Work, ia secondsystem of masses including a sieve drum rotatable around itslongitudinal axis, a rotatable base rigid with sai-d sieve drum, arotatab'le closure member rigid With said base and a rotatable shellrigid with said closure member, said shel'l having an iniet for thesupply of material to be centrifuged, the cross section olf said shellbeing smaller than that of said sieve drum, said shell surrounding saidclosure member at a predetermined distance and terminating at apredetermined distance from said base whereby a chamber yfor the supplyof material lto said sieve drum is formed, said closure member beingclosed at its end facing said inlet, and three resilient means betweensaid first and second systems of masses, two of said resilient meansopposing each other and resiliently holding one mass from the other, thethird such means resiliently connecting the vibrator to the second mass,all of .said resilient means yielding in the direction of thelongitudinal axis of the sieve drum for permitting vibrating movementsof said second system or masses in said direction of the longitudinalaxis of said sieve drum, said actuator imparting rotations to said sievedrum, and said vibrator imparting vibrating impulses to said sieve drum.

2'6. In a centrifugidevicea's 'claimed in 25, 'said :closuremembrrb'eing 'the shape of affustunl of hollow cone, and said is'hellbeingof conical shape. 4,

27. centrifugal device, comprising in combination: a 'rst systemof'iiiasse's includingaframe work, ari actuator for producing rotatingmovements and a vibrator :for pifoducing vibrating movements, saidactuator fand said V'vibrator being mounted on said iframe work, Yasecond system of `ir'rasses including a sieve 'drum rotatabile `aroundits longitudinal faxis, a rotatable base rigid with-said sieve drum, arotatable closure member rigid with said ba'se'and a rotatable shellrigid with said closure member', said shell having an inlet for thesupply of material to be centrifuged, the cross section of said shellbeing smaller than that of said sieve drum, said shetll surrounding saidclosure member at -a predetermined distance and terminating at apredetermined distance from said base whereby a chamber for the supplyof material to said sieve drum is formed, said closure member beingclosed vat its end facing said inlet, three resilient means between saidfirst and second system of masses, -two of said resilient means opposingeach other and resiliently holding one mass from the other, the thirdsuch means resiliently connecting the vibrator to the second mass, allof said resilient means yielding in the direction of the longitudinalaxis of the sieve drum for permitting vibrating movements of said secondsystem of masses in said direction of the longitudinal axis of saidsieve drum, and additional resilient `.means supporting .said firstsystem of masses resiliently, said additional resilient means yieldingin the dinection of the longitudinal axis of the sieve drum forpermitting vibrating movements of said first system of masses in saiddirection lof the ilongitudinal axis of said sieve drum, said actuatorimparting rotation to ,said sieve drum, and said vibrator impartingvibrating impulses to said sieve drum.

28. In a centrifugal device as claimed in .cl-aim 27, said closuremember being in the shape of a frustum of Va hollow cone, and said shellbeing of conical shape.

29. A method for dehydrating fine-granular material by means of acentrifugal device having a rotatable and vi-bratable conical sieve drumthe generatrix of which is inclined to the axis thereof by an angle ofapproximately 10-18, comprising the steps of rotating the sieve drum atsuch a number ci revolutions per minute that the centrifugal|acceleration at the mean perimeter `of the sieve drum equals about60-90 times the acceleration of gravity, and imparting to the drum avibrating movement having a frequency of about 25-35 cycles per secondand 1an yamplitude of approximately l-3 millimeters.

30. A method for dehydrating tine-granular material by means of acentrifugal device having a rotatable and vibratable conical seive drumthe generatrix of which is inclined to the axis thereof by an angle of10, comprising the steps of rotating the sieve drum at such a number ofrevolutions per minute that the centrifugal acceleration at the meanperimeter of the sieve drum equals times the acceleration of gravity,and imparting to the drum a vibrating movement having a frequency of 30cycles per second and an amplitude of 3 millimeters.

31. In a centrifugal device as claimed in claim 17, said frame Workincluding a hollow center shaft, said base of the sieve drum having anopening, said hollow center shaft passing through said opening into theinterior of said sieve drum, a first bearing arranged on said hollowshaft outside said sieve drum, a second bearing arranged on said hollowshaft inside said sieve drum, said first and second bearings rotatablysupporting said actuating means, said connecting rod passing through thebore of said hollow center shaft, and a cap arranged inside said sievedrum and rigid with the latter, said cap covering said second bearingand the portion of said hollow center shaft penetrating into theinterior of said sieve drum.

32. A centrifugal device comprising in combination: a first system ofmasses including a framework, an actuator for producing rotatingmovements and a vibrator for brator being mounted on said framework, asecond system of masses including a sieve drum rotatable around itslongitudinal axis, and a plurality of resilient means between said rstand second systems of masses including a pair of resilient meansopposing each other and resiliently holding one system of masses fromthe other and including a resilient means resiliently connecting thevibrator to the second system of masses, all of said resilient meansyielding in the direction of the longitudinal axis of said sieve drum,said actuator imparting rotations to said sieve drum, and said vibratorimparting vibrating impulses to said sieve drum.

References Citedv in the ile of thisrpatentt UMTED STATES PATENTSStillman sept. 9, 18784 Ljungstrom May ,7, 1907 Bok Feb. 11, 1908Armstrong Sept. 14,1915 Sorenson Sept.`2, 1941 Howe June 8, 1943 FOREIGNPATENTS Germany Aug. 10, 1934 Germany Feb. 23, 1942

